BIODEGRADATION OF KERATINOUS WASTES BY ALKALINE-KERATINASE PRODUCED FROM BACILLUS TEQUILENSIS BK206 AND OPTIMIZING THE CULTURAL CONDITIONS FOR INCREASED KERATINOLYTIC ACTIVITY

Keratinase-producing microorganisms can serve as a safe, environment-friendly, and cost-effective means for recycling and hydrolysis of keratin wastes and therefore play a substantial role in biotechnological applications. This study aimed to investigate the ability of Bacillus tequilensis BK206 to degrade keratin wastes, especially chicken feathers, and to measure its proteolytic and keratinolytic activity. The proteolytic and keratinolytic activity of the strain in different substrates was measured qualitatively and quantitatively. Then, the one-factor-at-a-time method was used to optimize the enzyme production. Optimization of the conditions (temperature 37°C, pH 10.5, feather concentration 2%, and ammonium chloride as a nitrogen source) increased the keratinolytic activity of the isolate by 2.3-fold. The alkaline pH was found to have the highest effect on the keratinolytic activity. The isolate was able to degrade chicken feathers completely and breakdown sheep wool, and hoof to a large extent. The results demonstrated the potential of Bacillus tequilensis BK206 is a potent keratinase-producing bacterium in treating various keratinous wastes in a safe, inexpensive, and easy-to-implement ecological process. Also, our alkaline keratinase is a good candidate for use in various industrial processes, especially in detergent and leather industries.